1. Field of the Invention
The rose chafer, Macrodactylus subspinosus (F.) is a serious pest of fruit crops, ornamentals, and flowers in eastern North America. Grapevines are a favorite food of the beetles. They begin their attack at blossom time and devour blossoms and newly set fruit, often destroying an entire crop. Other known host plants are peony, rose, blackberry, raspberry, pear, apple, plum, cherry, corn, Scots pine, and many ornamentals. At present, there is no attractant used for monitoring and possibly controlling adult chafers. This invention relates to compositions that are strongly attractive to rose chafers.
2. Description of the Prior Art
Trapping of the rose chafer was first reported by Johnson [Conn. Agr. Exp. Sta. Bull. 434: 314 (1940)]; however, the attractant used was not named. Williams et al. [J. Econ. Entomol. 75: 196-198 (1982)] disclose that valeric acid and hexanoic acid (caprioc acid) are individually attractive to the rose chafer. They also teach that a binary mixture of eugenol and hexanoic acid is attractive to the chafer, but that the attraction of the mixture is due to hexanoic acid alone and that there is no advantage to using the mixture. Williams et al. [Research Circular 272, Fruit Crops, pp. 38-40 (1982)] also tested a large number of acids, anhydrides, acid chlorides, and aldehydes individually as chafer attractants, but none were found superior to valeric acid and hexanoic acid.